This is from a judge who educated trump's lawyer on gender.From the link that you posted:
Sex refers to a set of biological attributes in humans and animals. It is primarily associated with physical and physiological features including chromosomes, gene expression, hormone levels and function, and reproductive/sexual anatomy
So then sex is an immutable trait. It is not "assigned" by anyone. It is identified at birth. There is no ambiguity.
Athletic competition is restricted to members of the same sex. Regardless of what your self-described gender is.